Glossary
Budburst - the time of year (usually in the spring) when trees open their dormant winter buds to begin the expansion of new branches and leaves
Chilling requirement - the amount of time below a certain temperature (around 0°C) that a tree needs before it begins to track warm days in the spring
Heat sum - a way of measuring the accumulation of warm days needed in the spring by a tree before it will end its winter dormancy and begin spring growth. Also referred to as spring heat accumulation.
Chilling requirement - the amount of time below a certain temperature (around 0°C) that a tree needs before it begins to track warm days in the spring
Heat sum - a way of measuring the accumulation of warm days needed in the spring by a tree before it will end its winter dormancy and begin spring growth. Also referred to as spring heat accumulation.